Transmission and control therefor



Dec. 4, 1956 w. H. Du SHANE ETAL 2,772,652

TRANSMISSION AND CONTROL THEREFOR :s sheets-sheet 1 Filed April 8, 1955FIG. 2

V'SPEED SELECTOR i3 SPEED SELECTOR' RANGE CAM Dec- 4, 1956 w. H. DUsHANE z-:TAL 2,772,652

TRANSMISSION AND CONTROL THERFOR Filed April 8, 1955 3 Sheets-Sheet 2FIG.3

RANGE CAM CLUTCH D TRACK CLUTCH A TRACK so 4 e670 CLUTCH c-r 68 `"CLUTCHB SPEED CAM ne HATCH B '02 6 cLUTcH c |40 TRACK we ||4 RANGE CHANGES l(RANGE cAM) F I G 8 FIG.9

IN VEN TORS W. H. DUSHANE SELECTOR V. E. RUGEN SPEED SELECTOR @QL-T@ RRR Dec. 4, 1956 w H, DU SHANE ET AL l 2,772,652

` TRANSMISSION AND CONTROL THEREFOR Filed April 6,l 1955 s sheets-sheets SPEED CHANGES (SPEED CAM) INVENTORS W. H. DuSHANE V.l E. RUGENTRANSMISSION AND CONT ,Wallace H.'Du Shane, Waterloo, and vVernon L.l`Rugen,

Cedar Falls, `Iowa, assignors to Deere Manufacturing Co., Dubuque, Iowa,a corporation of Iowa .Application A ugust 8, 19,55, Serial No. '526,97113 Claims. (Cl. 74-3375) This invention relates to arvehicletransmission-and control therefor and .more particularlyl to fatransmission ofthe multi-range, multi-speed type in which .the number ofspeeds in the transmission is multiplied vvby thedoubling `of speedratios through the useof dual-.range means.

A transmission of this. general. characterhas many, advantages,.not onlyfrom the standpointof Vreduction in the number of gears buty also in the,Way of iiexibility and particularly in the adaptation thereof to anagricultural tractor, for example, in which it is desirable ,-to.` have`a transmission that will produce a large numberof-ground speedsfthatvaryin relatively small-increments. Y,At .the

same time, it is desirableto have a transmission that .will

produce a relatively high transport speed for loperation i of thetractor onh1ghways and other good roads.` lMoreover,- a transmission ofthe class referredto is;:apable ofproducng alarge number-of speeds inreverse.

A transmission having the generalattributes discussed above forms thesubject of the'U. S.Y2,7l0, k546-10 Du- Shane and Rugen. In thattransmission, dual-rangemeans is provided for driving a countershaftfrom an input shaft at either high or low ranges in a forward-directionand at least asinglerange in reverse. Moreover, second means is providedin the transmission Afor driving kan output shaft at any one of fourspeeds Vfromzthecounter- .,shaft. Actually, the transmission is capable,ofproducing `eightfspeeds forward and four speeds in reverse; although,

1in the commercial adaptation thereof the highest reverse speed isrendered inoperative, because it wouldbertoo high-for practical use.

, The present inventionfhasl as one-of .its more significant objects theprovision of .control means Vfor-shifti ngthe @gears or clutches in atransmission of the ,typeljust re- ;ferred-lto. lSpecitcally,it is anobject of the inventionto -autilize improved cam means having cam-tracks therein for is disclosed in` detail in the ensuing specificationand, ac-

companying sheetsy of drawings, the several iignregpf which aredescribed immediately below.

Fig. 1 is a fragmentary elevational view, partly in section,illustrating a transmission and control mechanism v associatedYtherewith.

Fig. 2 isa fragmentary Yview asseen .inthe directionof the-arrowsv onthe line 2.1-2 of Fig. '1.

,- Fig.'` 3 is-a sectional viewas-seenza-long thellineffa-S Of Fig. l.

United States Patenti() .require no separate numerical designation. 26is keyedtoa front part of they input shaft and serves y,only to drive apowertake-off shaft` (notshown) for thevehicle. This pinion plays noimportantpart inthe ,.clescription to follow.

2,772,652 Patented Dec. 4, 1956 icc 2 Fig 4 is a sectional viewas seenalong the line 4-74 of Fig. l.

Fig. 5 is a View of the range-reverse cam as seen along Fig.y 6 is aview of the speed cam as seen along the line u 6 -6 fof Pig. 4.

Figs. 7, 8 .and 9 are individual views showing different positions ofthe range-reverse cam.

Fig. 10 is a fragmentary sectional view, on an enlarged scale, 3als seenalong the line 10-10 of Fig. 1.

Figs. ,11,112, 13 .and 14 are individual views showingdifferentpositions of the speed cam.

yFigulSk is asectional view as seen along the line r15 -15 .of Fig. 1.

In .general lnthe interests of simplicity and brevity, many yof theparts herein will be designated by conventional nomenclature and'thissystem will'be carried over into` the claims. It should be understood,of course, that this -characteristic of the description is not to beconsidered as importing any limitations into the range of equivalents towhich the invention is entitled. The use of expressions -such as righthand and fleft hand is based upon the position of an observer standingbehind the vehicleand looking forwardly. Figures l and 2 are basic viewsin this respect. The front o f the tractorV is beyond the left handmargin of the sheet containing Figs. l and 2. In Fig. l0, for example,the right and left hand sides of the tractor 'are respectively at theright and left of the viewer, which corresponds to the position ofthetractor operator. The

4only'departure from this system is represented by Figures'S and 6.

Transmission The ytransmission is, incorporatedas a suitable part ofavehiclef.which itself may be largelyconventional. fhatuportion ofthevehicle serving as a transmission housing is designated Iby the numeralland this housing 40; tively, between which areappropriate,.journaled aninput shaft, acountershaft ,and an output shaft. These has appropriatefront and rear Walls 22 andw24, respecare appropriately labeled on thedrawings and therefore A pinion -The input shaft has journaled thereonin axially spaced `relationship a `low-range pinion 28 and ahigh-rangepinion 30. These pinions are individually `and selectively connectibletorotatewith the input shaft byV means of a biy. directionally movablevclutch A, ywhich -clutch is movable between aneutral position, alow-range position and a .high-rangeposition. The directionofmovementfonconnecting the low-range gear 28 to the input shaft is.indicated in Figs. l and 3 vby an arrow L.. The direction ofaslcomprising a sleeve 32 linearly shiftable along a shifter rod 34 thatparallels the input shaft. This rod is appr0pri ately carried atopposite ends in the transmission `housing 4nlovernent for effectinghigh-range .operation is indicated by ran arrow H. The clutch A may beofrany suitable construction.adaptedv for the purposes and is shown herewalls 2 2 and 24 (Fig. 1). The sleeve has rigidly secured shaft.

44 with the high-range pinion `30 and the other ring 38 y128..' "When`the clutch A is shifted in the'directio'n L, the

'thereto a pair of fork arms which embrace a pair of synchronizer rings38. A synchronizer member 40 is lsplined to a hub 42 which in turn issplined to the input One of the rings V3S has a splined connection has asplined connection 46 with the low-range pinion rear fork 36 firstcauses synchronization between the rear ring 38 and the synchronizermember 40, after which the splined connection at 46 is carried over tothe splined hub 42, thus connecting the hub 42, low-range pinion 2S andrear synchronizer ring 38 for rotation in unison. This positivelyconnects the low-range pinion 28 to the input shaft. Shifting of theclutch A in the opposite direction (direction H) first synchronizes thefront ring 38 and the synchronizer member 40, followed by positiveengagement between the high-range pinion 30 and input shaft hub 42 bymeans of carrying over the splined connection at 44 to the hub as thefront fork 36 carries the clutch to the rear.

The clutch A thus enables the input shaft to drive the countershaft ateither a high-range or a low-range, since the high-range pinion 30 is inconstant mesh with a countershaft gear 48 and the low-range pinion 28 isin constant mesh with a second counter shaft gear 50. Because of therange-effecting characteristic of the clutch A, it will hereinafter besometimes referred to as a range clutch. As already indicated, the useof the expression clutch is not intended to exclude equivalentmechanisrns.

The countershaft gears 48 and 50 are preferably formed integral with orotherwise fixed to the counter shaft for rotation therewith. The same istrue of third and fourth countershaft gears 52 and 54. The output shafthas journaled thereon in coaxially spaced apart relationship first,second, third and fourth output shaft gears 56, 58, 60 and 62; and thesegears are respectively in constant mesh with the countershaft gears 48,52, 50 and 54.

From the description thus far, it will be seen that drive means isprovided for driving the counter shaft in either of two ranges from theinput shaft, depending upon the position of the range clutch A. In thedrawings, the range clutch is shown in its neutral position but it willbe seen that it can be selectively shifted to either a lowrange positionor a high-range position. The drive means established by the gears48-56, 52-58, 50-60 and 54-62 serves as means, in conjunctionl with apair of speed clutches B and C, for driving the output shaft at any oneof four speeds. Because of the dual-range drive to the countershaft, thefour speeds just referred to are doubled, thus giving the transmissioneight speeds fOrward.

As best shown in Fig. 4, the clutch B comprises a hub 64 keyed to andaxially non-shiftable with respect to the output shaft and externallysplined to axially shiftably carry a clutch ring 66. The output shaftgears 60 and 62 respectively have externally splined hub portions 68 and70, either of which is selectively engaged by the ring 66 when shifted.The drawing shows the clutch ring in its neutral position. Control ofthe clutch B is accomplished by means of a shifter fork 72 integral witha sleeve 74 lthat is linearly slidable along a shifter rod 76 parallelto the output shaft and appropriately carried at its front and rear endsby the transmission walls 22 and 24.

The construction of the clutch C is similar to that of the clutch B.Clutch C has a hub 78 fixed to the output shaft and externally splinedto axially shiftably carry a clutch ring 80 which is selectivelyshiftable axially into engagement with one or the other of hubs 82 and84 respectively formed as part of the output shaft gears 56 and 58. Ifit be considered that clutch B has a neutral position from which it isshiftable to first and second speed positions, then it will be seen thatclutch C has a neutral position from which it is shiftable to third andfourth speed positions. The clutch C is under control of a shifter fork86 integral with a sleeve 88 that is linearly slidable on the shifterrod 76. In other words, the same shifter rod 76 carries both shiftersleeves 74 and 88.

The respective pitch diameters of the low-range pinion 28 to thecountershaft gear 50, the high-range pinion 30 to the countershaft gear48 and the countershaft gears 48, 52, 50 and 54 respectively to theoutput shaft gears 56, S8, 60 and 62 are such as to give, in low-range,the following speeds forward: first, second, fourth and sixth; and inhigh-range, the following speeds forward: third, fifth, seventh andeighth. For example, with the clutch A establishing low-range drive from28 to 50, clutch B when shifted to the right as seen in Fig. l, willestablish drive from 54 to 62 to the output shaft and will produce firstspeed. Under the same conditions of the low-range position of clutch A,shifting of clutch B to the left in Fig. 1 will produce sixth speedforward. Clutch C when shifted to the right will produce second speedforward and when shifted to the left will produce fourth speed forward,assuming that clutch A is in its lowrange position. When clutch A isshifted in the opposite direction (to the right) to establish drive fromthe highrange gear 30 to the ycountershaft gear 48, clutch B whenshifted to the right will produce third speed and when shifted to theleft will produce eighth. Clutch C when shifted to the right willproduce fifth speed and when shifted to the left will produce seventh.

The transmission is capable of producing four speeds in reverse;although, as already indicated, the fourth of these speeds would be toohigh for practical usage and is therefore blocked out. The reversespeeds are accomplished by the use of a fourth clutch, here identifiedas the reverse clutch D. As best seen in Fig. 3, the input shaft haskeyed thereto a hub 90 on which is axially shiftably keyed asynchronizer member 92. A reverse pinion 94 is journaled on the inputshaft and is externally splined to axially shiftably carry asynchronizer ring 96 under control of a shifter fork 98. The fork isconnected to a sleeve 100 slidable on the upper or range shift rod 34.When the clutch D is shifted to the left or in the direction R as seenin Fig. 3, the ring 96 remains in engagement with the reverse gear 94but slides over onto the splines of the input shaft hub 90,synchronization being first effected between the ring 96 and thesynchronizer member 92. Under these conditions, the clutch A will be inits neutral position.

'I'he countershaft in Fig. 1 is shown somewhat displaced from its trueposition, which liberty has been taken in the interests of clarity. Theactual position of the countershaft is such that the output shaft gear62 is in constant mesh with the reverse pinion 94. Therefore, thereverse pinion 94 directly drives the output shaft gear 32 without theinterposition of the countershaft; although, since the countershaftgears are in constant mesh with the output shaft gears, the countershaftwill rotate idly when clutch D is engaged and clutch A is disengaged.Because the gear 62 is journaled on the output shaft, engagement ofclutch D alone does not establish reverse drive. In addition, theclutches B or C must be used. One speed in reverse may be achieved byshifting clutch B to the right so as to engage the output shaft gear 62.The speed ratio will be that between the reverse pinion 94 and theoutput shaft gear 62. Another reverse speed may be achieved by shiftingthe clutch B to the left, to connect the output shaft gear 60 to theoutput shaft. The speed ratio is then that resulting from constant meshbetween 94 and 62 and between 62 and 54, since 62, when driven by thereverse pinion 94, always drives the countershaft through thecountershaft gear 54. Two other reverse speeds are available byselective shifting of the clutch C.

Cam shifting means Idirection as respects the rockshaft.

.veniently-f-referred to yhereinvas a rangefcam. .'Ihiscam is so labeledin the 'drawingsiand will k notbe;numerical-ly identified. As best shownin-,Fig..,3, the transmission housing 20 has aleftihand 4lsidewall 102which journals a shortrockshaft 104 on an V-axis normal-,to the `axis ofthe shifter rod` 34. The portion of the -rockshaft in- Yternally of thewall 102 is keyed to the-.hubof therange cam andthe range camprojectsrearwardlyin a radial fThe-planeof the face of the range caml isvertical and the gshifter lsleeve 32 for -the clutch A yhasaihorizontally outwardly pro- Yjecting pin or follower 106whichyisslidably received in and guided by a cam track ridentied andlabeled yas the clutch A track. The shifter ,sleeve 100 -for clutch IDhas a horizontally outwardly projectingpinwor follower 108 which isreceived .in aclutchiD track in the range cam. The neutral position .ofthe range cam is releasably'retained bya. detent 110 which isselectively cooperative with a neutral?, notch'N. The range cam furtherhas in its-outer face, on an =arc on which the notch N lies, othernotches R, H and L, respectively for` reverse,

.high-range and low-range.

`The clutch A and clutch D tracks are, clearly. shown in Fig. 5, inconnection with which it tshould be remembered that this view shows .therange cam from its opposite side as distinguished from the illustrationofthe range cam in Figs. 1 and 7 through 9. .In the latter group offigures, thecenter -line of the track has been shown by vin oppositedirections, and these'high and low portions are separated by or merge atan intervening neutral portion 112. The relationship of thehigh,Llow-and Ineutral portions is such that rocki-ngof the cam ,causesshifting of the, clutch A among its neutral, high and lowrpositions.

-`For example, `the neutral p osition of the range ,camis shown in Figs.l and 5, as wellias in Fig. 3, wherein it will Vbe noted that the detent110, releasably fixes the vneutral position of the cam. If the ycarnisrocked upwardly (Fig. 9) the detent 110 is released from the neutralnotchand enters the-lowlor L notch. Theoffset of the track portion Ltoward the rockshaft 104 causes shifting of clutch A in a forwarddirection (arrow -L in Fig. 3). In other words, the follower106 iscausedto departto the left of itsy neutral position and of coursecarries the clutch A in the directionnecessary to engage clutch A foreffecting low-range drive between the input shaft pinion 28 and theinput shaft. If the rangedcam is rocked from the neutral position ofFig. l in a,clock wise direction to the position of Fig. 8,- thefollower 106 is displaced by the high track portion and the detent 110engages in the H notch. ClutchA is then shiftedin the opposite directionto establish high-range drive.

kItis a featureof the rangecamthat it serves alsoto control the reverseclutch D. Accordingly, the clutch D track has a neutral portion N ofsubstantial angular extent. This N portion in the clutch D track issubstantiallyangularly coextensive with the portion of the clutch Atrack that includes vthe highand lowy portions and the portion 112. Thereason for this is that clutch D must not be shifted while clutch Aisbeing engagedand disengaged. The effective portion of the clutch Dtrack,

-theclutch A follower-.106then rides in the neutralportion N oftheClutchA-track. -Again, the arrangement is such that the clutches -maybeshifted individually-but --cam is in its -neutral position.

of the Aclutch Bv track. design is such that onlyone ortheother ofclutches B Vand lC may be shifted, but not bothsimultaneously.

not;,simultaneously. A Fig. 7 shows ,the position ofi-he range ,carnwhenrit hasshifted the clutch D toits engaged .position toes'tablishreversedrive. The follower 106,for

the clutch A yremains in neutral.` Figs. 8 ,and` 9@show that thefollower 108 for the clutch D remains in neutral during the engagementand disengagement of theclutch A- as the clutch A follower-106 followsthe active portions of theclutch A track. The relative position of thecam with respect tothe range obtained can be .seen by-noting thelocationsof the R, H, N and Ldetent notches inthe cam. These notcheshave been shown in radial r-alinement with their respective trackportions.

The foregoing principles have Vbeen applied to means for effectingindividual shifting of clutches B and C.

l-"l`he-principal component in this varrangement is aspeed cam, labeledas -such and requiring no numerical designation. This camis carried by arockshaft 114 which is journaled in-the transmission side wall 102 yandithas a plurality of -angularly spaced 'notches for cooperation with adetent 116. The central notch ofthe group vof notches is aneutral or Nnotch and is shown as ;engaged -bythe detent in Figs. 1 and 4, becausethespeed Hence, both clutches B and C-'are-in-their-neutral ordisengaged positions. The

lspeed-.cam hasa clutch-B track and a clutch C track which respectivelyreceive followers 118 and 120, these followers `being respectivelyconnected to the sleeves yi74and S8 for the clutch'B and clutch Cshifters.

The :clutch B track yis effective to accomplish first, third, sixth andeighth speeds, it beingremembered that first and sixth fare in thelow-,range and third and eighth Dare in ,thehi-gh-range. Accordingly,the-clutch B track has an intermediate neutralportion N of appreciableangular length. The track is offset at one end to provide -an activeportion designated 6 8. The opposite endof the track is-osetleccentrically in the oppositeL direction and hasan activeportiondesignated 1 3. As the cam is rocked about its axis at l114 and passesthroughithenN range, thefollower .118 remains stationary. -However,additional angular'movement will cause they follower to be displace byeither the 6 8 track portion or the 1 3 trackportion, Vdepending uponthe direction of angular movement. kAmong the group of detent-receivingnotches,

--of which the neutral notch N is one, there are a 6 8 notch and a 13vnotch, respectively alined radially with the 6 8 and 1 3 trackportions. This will be clear from lFigs. '1l and 14. Fig. 11 shows thecam in vits 6 8 position and Fig. 14 shows thel cam in'vits :1 3

. position. Theposition of the detent 116 in its respective knotch willserve as a designation of the position of the cam. The clutch B trackhas been shown in dot-dash lines in Figs. l and 11 through 14.

The clutch C track is operative -to control clutch C-for effectingrsecond, fifth, fourth and seventh speeds. Ac-

ycordingly, this track'has a pair of neutral portions Nan- `gularlycoextensive and radially yalined with the 1 3 vand 6 8portions of clutchC track. In addition, 4'clutch C track has offsetportions '4 7 and 2 5,these portions being within the angular range of -theneutral vportionNAgain, the principal of the-cam Detent-receiving notches 2 5 and 4 7 areincluded in the aforesaid group of notches and are radially alinedrespectively with the track-portions 2 5 and 4 7. In-

termediate the 2 5 and 4 7 ytrack portions is a v'neutral portion ordwell 122, whichportion is radiallyalined with the neutraldetent-receiving notch N for the detent v 116. When the cam is in thisposition v(Figs. 1 and 6) both .clutches B and C are disengaged. Fig. 12shows the position of the follower 120 when the speed camyis inaposition to engage clutch C for accomplishing-second Ior fifth speed.Fig. 13 shows the. 4 7 position of the speed cam. In kconnection withthe positionsofv the speed ycam as shown in Figs.v 1 and `11 throughf14,.it,

should be remembered that any one of these positions is also eiective tocontrol the appropriate clutch (B or C) to obtain reverse, if the clutchA is in neutral and the clutch D is engaged. As indicated above, theforegoing is subject to the limitation that the fourth speed in reverseis not used as a practical matter.

In Figs. 1 and 1l through 14, as in Figs. 1 and 7 through 9, theassociated track portions can be determined frorn the positions of thedetent notches, which have been appropriately designated according tothe speed or neutral position obtained.

Control means The basic components of the control means are best shownin Figs. 2 and 10 and in the upper portion of Fig. l. Any suitablesupport, represented here by the numeral 124, journals coaxiallyintersleeved rockshafts 126 and 12S. The interior rockshaft 126 is arange rockshaft and has keyed to the left hand thereof an arm 130 whichis connected by a link 132 to an arm 134 that is keyed to the outer endof the range cam rockshaft 104. Hence, rocking of the rockshaft 126 willeffect angular movement of the range cam. The external rockshaft 128 haskeyed to its left hand end, just inwardly of the arm 130, an arm 136which is connected by a link 138 to an arm 140 that is keyed to theouter end of the speed cam rockshaft 114. Because the rockshaft 12Scontrols the speed cam, it will be hereinafter sometimes referred to asa speed selector rockshaft.

The right hand end of the speed selector rockshaft 128 carries a speedselector having an upstanding sectorshaped portion 142 and a dependingportion 144.V The upper portion 142 terminates in an arcuate flange 146which faces to the right and has its marginal edge interrupted by asingle notch 148. the range selector rockshaft 126 has keyed thereto arange selector having an upper sector-shaped portion 150 and a lowerportion 152. The upper portion 150 is substantially coextensive with theupper portion 142 of the speed selector when both selectors are in theirneutral positions (Figs. l, 2 and l0), and the range selector upperportion 150 terminates in an arcuate flange 154 which extends toward themarginal ange 146 on the speed selector. The marginal edges of theflanges are closely proximate, preferably such as to afford only workingclearance. The flange 154 on the range selector is interrupted by aplurality of notches, here four, designated respectively by the numerals156, 158, 16) and 162. Since the speed and range selectors are keyedrespectively to the speed and range rockshafts 128 and 126, rocking ofthe respective selector will effect angular movement of the respectivecam through the associated linkage previously described. However, it isdesired that the selectors be movable independently and notsimultaneously. For this purpose, there is loosely mounted on orjournaled by the rockshaft 126 a carrier 164 which is interposed orsandwiched between the hubs of the selectors. This carrier has a pivot166 normal to the axis of the rockshafts and this pivot mounts theforked lower end of a shift lever. The shift lever, like the twoselectors, is labeled in the drawings and needs no numericaldesignation. The shift lever extends radially from its position on therockshaftmounted carrier 164 and when the selectors are in their neutralpositions, the shift lever extends through the notch 148, the crosssectional area of the shift lever and the size of the notch 148 beingcommensurate. Moreover, the portion of the range selector ange 154intermediate the notches 158 and 160 constitutes a bar or blockingportion so that the shift lever cannot escape from the notch 148 whenthe selectors are in neutral (Fig. 2). This requires that the shiftlever be used first to shift the speed selector until the shift lever isalined with one of the notches 156, 158, 160 or 162 in the rangeselector.

Biasing means 168 operates between the carrier 164 andl The proximateend ofv a cam surface 170 to resiliently urge .the shift lever to theleft or into the notch 148.

A shroud or panel 172 affords a plate in which is formed an aperture 174for dening the path of movement of the shift lever. The portions of theplate that define opposite ends of the aperture limit angular movementof the shift lever and as will be seen a rearward edge portion 176blocks out the fourth speed in reverse. The plate 172 also serves tocarry indicia for making readily visible to the operator the respectivepositions of the shift lever according to the speed selected in thetransmission. For example, the left hand marginal edge of the aperture174 is labeled, as shown, 1-3-R, 2 5-R, 4-7-R and 6-8. The right handmarginal edge of the aperture 174 is labeled L, N, H and R. The lettersL, H and R correspond respectively with the notches 158, 160 and 162 andthe letter N corresponds with the bar portion that intervenes betweenthe notches 158 and 160. As shown, the flange 154 of the range selectorcarries an arrow head which is alinable with any one of the letters L,N, H or R.

Another feature of the invention is the interlock means for preventingsimultaneous movement of the speed and range selectors and forcompelling initial movement of the speed selector before permittingmovement of the range selector. The details of the interlocking meansare best shown in Figs. l, l0 and l5. As shown there, the support 124includes an upstanding member or ear 178 which is apertured at 180 tocarry a detent ball 182. The range selector lower portion 152 hastherein a single notch 184. The lower portion 144 of the speed selectorhas four notches therein, labeled respectively from front to rear as1-3-R, 2-5-R, 4-7-R and 6 8. When both selectors are in neutral, thedetent ball 182 is received in part in the notch 184 in the rangeselector and movement of the ball out of that position is opposed by aspeed selector lower portion blocking element intervening between the25R notch and the 4-7-R notch. In other words, the size of the ballrelative to the size of the aperture and depth of the notch 184 is suchthat the speed selector in its neutral position locks the ballpositively in the notch 184 in the range selector. Therefore, the rangeselector cannot be moved until the speed selec tor -is first moved toone of its speed positions. For example, if the speed selector is firstmoved to its 2 5-R position, the 2 5-R notch registers with the ball182. At the same time, the shift lever in the speed selector notch 148registers with the notch 158 in the range selector. Therefore, the shiftlever may be moved to the right and into the notch 158. Thereafter, theshift lever can be moved fore or aft to rock the range selector. As therange selector moves out of its neutral position, it establishes apositive block on the ball 182, because of the unnotched oppositeportions of the range selector lower portion 152. Therefore, thearrangement is such that neither of the selectors can inadvertently moveout of its set position and there is no danger of improper operation ofthe transmission.

Operation The operation of the transmission and control therefor may bebest understood from a description of a complete cycle of speed andrange selection. For present purposes, it is assumed that all of thecomponents are in their respective neutral positions and it is desiredto shift the transmission to obtain rst speed forward. Ignoring for thepresent the effects of whether or not the main engine clutch (not shown)is engaged or disengaged, the operator first moves the speed selectorforwardly, since the shift lever is engaged with the speed selectornotch 148. This will aline the shift lever with the index 1-3-R on theguide plate 172 and at the same time will register the shift lever withthe notch 156 in the range selector flange 154. Simultaneously, the1-3-R notch in the speed selector lower portion will register with theinterlock detent 'Iball 1182 and, willfthereforepermit movement oftherange selector. HWith theshift leverin the range selector :notch5156,the'range selector is `moved forwardlyuntilathe -arwwf-registerswith the'letter L at .the-right hand side of the --guide faperture '174. The transmission is4 now operating'in first speed, since irst speedis -in the-z group 'of low- -range-speeds. As previously described,-frst speed is obtained by moving the speed cam-in acounterclockwisedirection to ,displace clutch B follower 1-18 to fthe -rear (iFig.1'4'). In other Words, forward movement yof the -shift lever to the.l-SFR position is counterclockwise movek-ment -andthe forces .thusdeveloped tare transmitted l-throughathearrn `136, link 138 and arm 140to the speed cam--rocks'haft 1114. As vthe speed cam proceeds to itsFig. .14.or E1-3R.position, ,the clutch 'C track causes the clutch'Cfollowerv120 to. move tothe position of Fig. l2 and then back-toneutral, and it remains -in neutral as it is guided -by lthe-lower.concentricportion-of clutch C track. The fact :of engagement:and'then disengagementr of clutch C is -immaterial because the clutchesA and VB `are per-force disengaged.

' -I..ikewise,as the range v`selector is movedforwardly to alinee'thearrow thereon with the L on the plate 172,*the movement iscounterclockwise, which is transmitted through the arms 130 and134-andlink 13:2 4to the range camfor moving that camangularly ina'counterclockwise rdirection. Therefore, the range :cam moves lfrom the:.neutral. position of Fig. l to the low position offFig. 9. The reverseclutch D is not disturbed, since its follower "108. follows the neutralorconcentric portion of ,its track.

@While :the-speedy selector -remains in its 1,-3-R/position a(alreadyselected), therange selector may be-moved to its high gor reverseposition. yIf it is moved toitshigh Y.p o sition,git shifts clutch A inthe H direction and .the transmission now operates in third speedforward, since E .third .*speed is the high-range counterpart vof low-.irangeirst speed. :Aga-in,` -the position of clutch ,Dy is notdisturbed. EQne speed -in lreverse may-be Aobtained rby @leavingYthefspeed selector in the position already selectedAandzby-ftzontinuiug, movement ofthe rangeselectorin arearward;direction until the y arrow registersy `with sthe lettergRtatthejright hand side-of-,theguideaperture v1,74. -Clutch.-A r emains finneutral andclutch D- is engaged. @Since clutch B fhas beenrensaged bymovement thereof to the-rear orto, the right, reverse drive is; from thereverse lpinion-.Qd-.v-,to thetoutput gear 62 and directly `to the-output shaft, since shifting of clutch B to the right .,or y,to-the.freanteffetits;teugagementrbetween -its clutch- ^`ring-166Y and.it-heftocthed bmbf/ onthe utp11tsear :62 .(see Fis- 4)- Flexibility inobtaining .the .other ,speeds Vfollowsyfrom -thefforegoing -v Inshort,;-the.Y speed selector;isfirst-,moved -to. select :a group .ofyspeeds, vwhich will be determined-by Ithegjdirection tofshiftingof-onepr the otherof clutches B .and .C. Hence each group lcontains .three Speeds.. with 1 ,the exception iofI l the '6 8group-which, asgpreviouslydescri-bed, may-befblockedput because ofthefconguraton @of fthe guide aperture j atl-7 6. 'This relationship tis yasptolsusa-gement with the, D Otch $1.48 ein the, speed selector,vvis- ,moved fHench,-;theshift lever ,may `be shifted tothe,rightrand-iinto .-t-he inotc'h :1.62. INowthe .portion .-176 constitutesa limitation tonrearwa'rd movement of the range tlselector,because,nas.Willvfbefreadily-.seem the distance between the .notch-.162.and the vportion 176- corresponds yrelatively .-,withtheA distance`between the arrow and -.the index \H. ITherefore, rearward 1movement ofthe range selectorl vis A:limited to its high-position. T here is no:limit on y.its vforward. position, vas arnonglow, neutraland high.

,Summary transmissionsand -control rprovidedfitherefor is characterizedA`by :extreme vsimplicity -andfexibilitm con- `r10 Sideringf theelevenspeeds =l2yspeeds availableyprodueed thereby, all under-controlpfa'single -shift leverfand/a pair of selectors. The interlock meansyprevents inadvertentfshifting of either,selector in those .cases in.which selector-movementmay be accomplished by some yinstrumentalityother thanthe shift lever. The tracks inthe respective -cams affordsequential 4operation' in a desirable yorder, al1-based uponexperiencein thesequence of speeds .needed in eicient tractor operation. Thesecan, of course, -be varied to suit individual desires.

tures of the invention -not categorically enumerated hereing willundoubtedly occur to -those versed in the art, as will manymodifications and alterations in the structure disclosed, all of whichmay be achieved without departing from the-spirit and scopeof theinvention as dened in the appended claims.V

What is claimed is:

l. A transmission and control therefor, comprising: input, output andcountershafts; vmulti-range drive means for driving the countershaftfrom the input shaft and including a-rangeclutch shiftable among neutraland first and-second active positions; multi-speed drive means-fordriving the output shaft from the countershaftand-including aspeedclutchshiftableamong neutral and first and second active positions; aspeed selector movable among neutral and rst and second yactivepositions for achieving corresponding positions of the speed clutch'andhaving a laterally opening shifter-receiving notch; afshifter alongsideand movable relative to said selector both laterally of .and parallel toysaid lselector and normally received in said notch; and a rangeYselector movable parallel and relative to the speed selector amongneutral and rst and second active positions for achieving correspondingpositions 'of the range clutch, said range selector having a bar portionopposed to the speed selector notch when both -selectorsvare in neutrallso as to confine the Shifter to'the speed selector notch, said rangeselector having additional notches angularly. offset from said barportion so thatuafter the speed selector is moved by the shifter toeither active position independently of the range selector'said shiftermaybe'moved laterally into one of said range `selector notches wherebysaid shifter may ymove said rangeselector .toeither of its activepositions drive means for driving the output shaft from the countershaftandhinc'luding a speed clutch shiftable among neutral and first andsecond active positions; a speed selector .movableamong neutral andrstand second active positions for achieving COrrespOIldingpositions of thespeed clutch and .having a laterally opening shifter-receiving vnotch;ashifter alongside and movable relative to said selector both laterallyofand parallel to said selector and normally received in said notch; anda range selector movable parallel andrelative to rthespeed selectoramong neutral, high-range, low-range and reverse positions for achievingcorresponding positions of the range clutch, said range selector havinga bar portion opposed to the speed selector notch when both selectorsare in neutral so as to confine the shifter to the speed selector notch,

said range selector having additional notches angularly offset from saidbar portion so that after the speed selector ismoved by the shifter toeither active position independently of the range selector said shiftermay-be moved laterally into one of said-range selector -notcheswherebysaid-shifterimay move sai'drange selector `to any Other fea-` ofits aforesaid high-range, low-range and reverse positions independentlyof the speed selector.

4. A transmission, comprising: input, counter and output shafts; anddrive means for driving the countershaft forwardly from the input shaftat either a high-range or a low-range or reversely in at least onerange, including a range clutch shiftable axially on the input shaftamong neutral, high and low positio-ns and a reverse clutch shiftableaxially on the input shaft between neutral and reverse positions; arange-reverse cam rockable about an axis and having a range track and areverse track and range and reverse followers respectively in saidtracks and respectively connected to the range and reverse clutches,said range track having a concentric portion defining the neutralposition of the range clutch and angularly spaced portions offseteccentrically in opposite directions and respectively defining the highand low positions of the range clutch, said reverse track having aconcentric portion defining the neutral position of the reverse clutchand an eccentric portion defining the reverse position of said reverseclutch and the concentric portions of each track being radially alinedwith the eccentric portions of the other track; multi-speed drive meansfor driving the output shaft from the countershaft at any one of first,second, third and fourth speeds, including a first-second clutch axiallyshiftable on the output shaft among neutral, first and second positionsand a third-fourth clutch axially shiftable on the output shaft amongneutral, third and fourth positions; a speed cam rockable about an axisand having a first-second track, a third-fourth track, and first-secondand third-fourth followers respectively in said tracks and respectivelyconnected to the first-second and third-fourth clutches, saidfirst-second track having a concentric portion defining the neutralposition of the firstsecond clutch and angularly spaced rst and secondportions offset eccentrically in opposite directions and respectivelydefining the first and second positions of the first-second clutch, saidthird-fourth track having a concentric portion radially alined with thefirst-second track portions and defining the neutral position of thethirdfourth clutch and third and fourth portions offset eccentrically inopposite directions and radially alined with the neutral portion of thefirst-second track and respectively defining the third and fourthpositions of the third-fourth clutch; selector means for rocking therange-reverse cam; selector means for rocking the speed cam; andinterlock means operative to compel individual operation of eachselector means.

5. A transmission, comprising: input, counter and output shafts; anddrive means for driving the countershaft forwardly from the input shaftat either a high-range or a low-range or reversely in at least onerange, including a range clutch shiftable linearly among neutral, highand low positions and a reverse clutch shiftable linearly betweenneutral and reverse positions; a range-reverse cam movable transverselyto the line of movement of the range and reverse clutches having a rangetrack and a reverse track and range and reverse followers respectivelyin said tracks and respectively connected to the range and reverseclutches, said range track having a neutral portion defining the neutralposition of the range clutch and spaced active portions offset inopposite directions from the line of movement of said cam andrespectively defining the high and low positions of the range clutch,said reverse track having a neutral portion defining the neutralposition of the reverse clutch and an active offset portion defining thereverse position of said reverse clutch, and the neutral portions ofeach track being alined with the active portions of the other track;multi-speed drive means for driving the output shaft from thecountershaft at any one of rst, second, third and fourth speeds,including a first-second clutch shiftable linearly among neutral, firstand second positions and a third-fourth clutch shiftable linearly amongneutral, third and fourth positions; a speed cam movable transversely tothe line of movement of the first-second and third-fourth clutches andhaving a first-second track, a third-fourth track, and first-second andthird-fourth followers respectively in said tracks and respectivelyconnected to the first-second and third-fourth clutches, saidfirst-second track having a neutral portion defining the neutralposition of the firstsecond clutch and spaced first and second activeportions offset in opposite directions from the line of movement of saidcam and respectively defining the first and second positions of thefirst-second clutch, said third-fourth track having a neutral portionalined with the first-second track portions and defining the neutralposition of the thirdfourth clutch and third and fourth portions offsetin opf posite directions from the line of movement of said cam andrespectively alined with the neutral portion of the first-second trackand respectively defining the third and fourth positions of thethird-fourth clutch; selector means for moving the range-reverse cam;selector means for moving the speed cam; and interlock means operativeto compel individual operation of each selector means.

6. Control means for a transmission of the character described,comprising: a support; first and second coaxial rockshafts carried bythe support for independent rocking; first and second selectors fixedrespectively to and extending radially from the rockshafts inside-byside relationship, each selector having an arcuate flange andsaid flanges facing toward each other and having their respectivemarginal edges closely proximate to each other, said first selectorflange having a single notch therein opening at its marginal edge andsaid second selector ange having a plurality of notches therein openingat its marginal edge and angularly offset from the rst selector notchwhen both selectors are neutrally positioned, whereby an unnotchedportion of each flange is directly opposite a notch in the other flange;a shifter sandwiched between the selectors and normally received in thefirst selector notch and confined thereto by the opposing unnotchedportion of the second selector ange; and means mounting the shifter forangular and lateral movement relative to the selectors, whereby saidtirst-selector-notchengaged shifter is effective to move the firstselector angularly until said shifter is opposite to and receivable by asecond selector notch to be moved laterally out of said first selectornotch and into said opposite notch for moving the second selectorangularly independently of the first selector.

7. The invention defined in claim 6, including: detent I means forreleasably locking the selectors in positions respectively correspondingto their notch and notches.

8. Control means for a transmission of the character described,comprising: a support; a first selector rockable on the support; asecond selector coaxially rockable on the support independently of thespeed selector and closely spaced laterally from said speed selector; amember rigid on the support and projecting into the space between theselectors, said member having an aperture therethrough parallel to therocking axis of the selectors; a detent in said aperture; the firstselector having a single notch therein receiving part of said detentwhen said notch and detent are in register and the second selectorhaving a blocking portion registrable with the aperture to confine thedetent to the aperture and said notch and thereby to lock said firstselector against rocking; said second selector having at least onedetent notch spaced angularly from said blocking portion and forreceiving part of said detent when said second selector is movedangularly, whereby the detent is released from the first selector notchto release said first selector for angular movement; and said firstselector having a blocking portion'adjoining said first selector notchand engaging and forcing the detent to lock into the second selectornotch when said second selector is moved angularly.

9. Control means for a transmission of the character described,comprising: a support; a first selector movable on the supports; asecond selector movable on the support parallel to .and independently ofthe speed selector and closely spaced laterally from said speedselector; a member rigid on the support and projecting into the spacebetween the selectors, said member having an aperture therethroughtransverse to the planes of movement of the selectors; a detent in saidaperture; the first selector having a single notch therein receivingpart of said detent when said notch and detent are in register and thesecond selector having a blocking portion registrable with the apertureto confine the detent to the aperture and said notch and thereby to locksaid first selector against movement; said second selector having atleast one detent notch spaced from said blocking portion in thedirection of selector movement for receiving part of said detent whensaid second selector is moved, whereby the detent is released from thefirst selector notch to release said first selector for movement; andsaid first selector having a blocking portion adjoining said rstselector notch and engaging and forcing the detent to lock into thesecond selector notch when said second selector is moved.

10. Control means for a transmission of the character described,comprising: a support; first and second coaxial rockshafts; first andsecond closely axially spaced selectors fixed respectively to andprojecting radially from the rockshafts for independently rocking saidrockshafts; a carrier journaled on one rockshaft between the selectors;a shifter pivoted to the carrier on an axis transverse to the rockshaftsand extending radially between the selectors yfor lateral movementtoward and away from said selectors; means on the rst selector includinga notch for receiving the shifter when the shifter is moved toward saidfirst selector, whereby the shifter and first selector are movableangularly in unison independently of the second selector from a neutralposition to a displaced position; and means on the second selectorincluding a notch for receiving the shifter when said shifter is movedlaterally in the opposite direction after movement thereof with the rstselector to said displaced position, whereby the shifter and secondselector may be moved angularly in unison independently of the rstselector.

l1. The invention defined in claim 10, including means biasing theshifter for lateral movement toward the first selector.

12. The invention defined in claim l0, including: a guide plate over theselectors and having an aperture through which the shifter extends, saidplate having angularly spaced portions dening opposite ends of theaperture and limiting angular movement of the shifter.

13. The invention defined in claim 10, including: detent means on thesupport and cooperative with the selectors, said detent means includinga positive lock controlled by the first selector in its neutral positionfor preventing angular movement of the second selector until the firstselector is first moved to its displaced position.

References Cited in the le of this patent UNITED STATES PATENTS 826,851Hendrickson July 24, 1906 854,480 Frayer et al May'2l, 1907 1,400,494Woodhull Dec. 13, 1921 2,031,807 Werner Feb. 25, 1936 2,667,082 Brocketal Jan. 26, 1954

